Phlegmasia Alba Dolens
Definition and context
Phlegmasia alba dolens ("milk leg") is an uncommon, limb‑threatening presentation at the severe end of the deep vein thrombosis (DVT) spectrum. It reflects near‑complete venous outflow obstruction-typically iliofemoral DVT-producing rapid, tense limb oedema that compromises arterial inflow.
If untreated it may progress to phlegmasia cerulea dolens with venous gangrene and limb loss. These syndromes are emergency manifestations of extensive proximal DVT and should prompt urgent escalation (NICE NG158).
Pathophysiology
Massive thrombosis of the iliac/femoral veins causes abrupt venous congestion with a rapid rise in interstitial and compartmental pressure. Early arterial inflow may be relatively preserved (pale, tense limb = alba), but increasing pressure impairs microvascular perfusion, leading to cyanosis, loss of distal pulses, venous gangrene and compartment‑type ischaemia (cerulea) if not promptly relieved.
Clinical features
- Rapidly progressive, unilateral lower‑limb swelling; limb tense and painful.
- Limb colour: pale/blanched in alba; cyanotic/mottled in advancing cerulea.
- Pain often severe and out of proportion.
- Reduced sensation and motor deficit may indicate evolving ischaemia or compartment syndrome.
- Pulses may be present early in alba but often become diminished or absent as cerulea develops.
- Possible systemic features from sepsis or pulmonary embolism in extensive thrombosis.